Maxtor hdd - unknown device and doesnt ask for drivers?

My external hard drive was working 100% up until today, and for no good reason upon connecting today to any usb port, it tells me it is an unknown device. The drive still whirrs when I connect the cable. What should I do? Windows simply says to try reconnecting it, or replace it. Reconnecting just gives me the same message. 500GB of data gone, and I was all set to get a second hdd as a secondary backup soon too :( any ideas on how to fix? thanks

thanks for the replies and tip about directly connecting to a pc motherboard as a last resort,its this one, built in fan, sata I think, and getting on a bit. Unfortunately the way these drives are built, i dont think removing the case would be a very easy job. Nothing seemed to show in device manager, although I may have just missed it. I likely bought it just after 2008. It hasnt been used on a constant basis, and its health has always shown as being very good. I know thats no excuse for not having that secondary backup, since drives can fail any time.

After trying a recommended sfc /scannow check from some random website, I managed to solve the problem (temporarily at least to be able to read it): I simply changed the USB cable. Which seems very odd for a temporary solution, as the one used beforehand worked perfectly yesterday, and I never change these cables on a regular basis. I was certain that the previous one was the original. Im now going to backup as much as I can onto another hd right now, but have you ever heard of an identical cable type having issues with an external drive? Im not having any issues browsing through and opening any of its content, so do you think it could still be the first signs of an aging drive? I always hear about the average hard drive lifespan being completely unpredictable and lasting anywhere between 2-6 years. Perhaps thats one reason as to why hdds are so cheap, lol, but the technology regarding lifespan has surely got to improve and become far more reliable when you consider the size hds are getting.

Do you think I should simply retire this external hdd, or simply do a secondary backup on a constant basis, continuing to use it?

Do you have secondary backups of everything important, or do you not put that content onto any of your older hds? Ive noticed with the usb cable that didnt work, there is a large '' symbol near the end, I assumed this was simply relating to maxtor, but now Im not so sure. On a slightly different more confusing note ive also noticed that there are type a and type b usb cables, so now im wondering if I had put the right cable in after all, since I do have other devices that use the same usb leads. Ill need to work out what other devices use the same type of cable and try the questionable cable with something else, to see if that really was the problem. If the cable works with any other device or hd, and the unconnecting hd continues to now work, and I cant find out about conflicting drivers through windows error logs or similar, then perhaps Ill never know what the issue was, but for now the panic is over, lol. No other systems to try the same hd on here at the moment.